﻿#region Legal Disclaimer
// THIS SOFTWARE IS PROVIDED UNDER THIS LICENSE ON AN “AS IS” BASIS, WITHOUT 
// WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT 
// LIMITATION, WARRANTIES THAT THE COVERED SOFTWARE IS FREE OF DEFECTS, 
// MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE OR NON-INFRINGING. THE ENTIRE 
// RISK AS TO THE QUALITY AND PERFORMANCE OF THE COVERED SOFTWARE IS WITH 
// YOU. SHOULD ANY OF THIS SOFTWARE PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT 
// THE INITIAL DEVELOPER OR ANY OTHER CONTRIBUTOR) ASSUME THE COST OF ANY 
// NECESSARY SERVICING, REPAIR OR CORRECTION. NO USE OF THIS SOFTWARE IS 
// AUTHORIZED HEREUNDER EXCEPT UNDER THIS DISCLAIMER.
// 
// Microsoft Public License (Ms-PL) governs use of this software. If you use the software, 
// you accept this license. If you do not accept the license, do not use the software.
#endregion
using System;
using System.Collections;
using System.Collections.Generic;

namespace SimplyConfigured.Factories
{
    /// <summary>
    /// 
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public class NotificationList<T> : IList<T>
    {
        private readonly IList<T> _base = new List<T>();

        /// <summary>
        /// Occurs when an item gets added to the collection.
        /// </summary>
        public event EventHandler<ItemChangedEventArgs<T>> ItemChanged;

        /// <summary>
        /// Called when an item gets added to the collection.
        /// </summary>
        /// <param name="sender">The sender.</param>
        /// <param name="e">The e.</param>
        public void OnItemChanged(object sender, ItemChangedEventArgs<T> e)
        {
            if (ItemChanged != null)
            {
                ItemChanged(this, e);
            }
        }

        //protected void Add(int index, T item)
        //{
        //    EventHandler<ItemInsertedArgs<T>> handler = ItemChanged;
        //    if (handler != null)
        //    {
        //        handler(this, new ItemInsertedArgs<T>(index, item));
        //    }
        //    _base.Insert(index, item);
        //}

        #region Implementation of IEnumerable

        /// <summary>
        /// Returns an enumerator that iterates through the collection.
        /// </summary>
        /// <returns>
        /// A <see cref="T:System.Collections.Generic.IEnumerator`1"/> that can be used to iterate through the collection.
        /// </returns>
        /// <filterpriority>1</filterpriority>
        public IEnumerator<T> GetEnumerator()
        {
            return _base.GetEnumerator();
        }

        /// <summary>
        /// Returns an enumerator that iterates through a collection.
        /// </summary>
        /// <returns>
        /// An <see cref="T:System.Collections.IEnumerator"/> object that can be used to iterate through the collection.
        /// </returns>
        /// <filterpriority>2</filterpriority>
        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }

        #endregion

        #region Implementation of ICollection<T>

        /// <summary>
        /// Adds an item to the <see cref="T:System.Collections.Generic.ICollection`1"/>.
        /// </summary>
        /// <param name="item">The object to add to the <see cref="T:System.Collections.Generic.ICollection`1"/>.</param><exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only.</exception>
        public void Add(T item)
        {
            _base.Add(item);
            OnItemChanged(this, new ItemChangedEventArgs<T>(item, ItemChangedEventType.ItemAdded));
        }

        /// <summary>
        /// Removes all items from the <see cref="T:System.Collections.Generic.ICollection`1"/>.
        /// </summary>
        /// <exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only. </exception>
        public void Clear()
        {
            _base.Clear();
        }

        /// <summary>
        /// Determines whether the <see cref="T:System.Collections.Generic.ICollection`1"/> contains a specific value.
        /// </summary>
        /// <returns>
        /// true if <paramref name="item"/> is found in the <see cref="T:System.Collections.Generic.ICollection`1"/>; otherwise, false.
        /// </returns>
        /// <param name="item">The object to locate in the <see cref="T:System.Collections.Generic.ICollection`1"/>.</param>
        public bool Contains(T item)
        {
            return _base.Contains(item);
        }

        /// <summary>
        /// Copies to.
        /// </summary>
        /// <param name="array">The array.</param>
        /// <param name="arrayIndex">Index of the array.</param>
        public void CopyTo(T[] array, int arrayIndex)
        {
            _base.CopyTo(array, arrayIndex);
        }

        /// <summary>
        /// Removes the first occurrence of a specific object from the <see cref="T:System.Collections.Generic.ICollection`1"/>.
        /// </summary>
        /// <param name="item">The object to remove from the <see cref="T:System.Collections.Generic.ICollection`1"/>.</param>
        /// <returns>
        /// true if <paramref name="item"/> was successfully removed from the <see cref="T:System.Collections.Generic.ICollection`1"/>; otherwise, false. This method also returns false if <paramref name="item"/> is not found in the original <see cref="T:System.Collections.Generic.ICollection`1"/>.
        /// </returns>
        /// <exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only.</exception>
        public bool Remove(T item)
        {
            var result = _base.Remove(item);
            if (result)
                OnItemChanged(this, new ItemChangedEventArgs<T>(item, ItemChangedEventType.ItemRemoved));

            return result;
        }

        /// <summary>
        /// Gets the number of elements contained in the <see cref="T:System.Collections.Generic.ICollection`1"/>.
        /// </summary>
        /// <returns>
        /// The number of elements contained in the <see cref="T:System.Collections.Generic.ICollection`1"/>.
        /// </returns>
        public int Count
        {
            get { return _base.Count; }
        }

        /// <summary>
        /// Gets a value indicating whether the <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only.
        /// </summary>
        /// <returns>
        /// true if the <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only; otherwise, false.
        /// </returns>
        public bool IsReadOnly
        {
            get { return false; }
        }

        #endregion

        #region Implementation of IList<T>

        /// <summary>
        /// Determines the index of a specific item in the <see cref="T:System.Collections.Generic.IList`1"/>.
        /// </summary>
        /// <returns>
        /// The index of <paramref name="item"/> if found in the list; otherwise, -1.
        /// </returns>
        /// <param name="item">The object to locate in the <see cref="T:System.Collections.Generic.IList`1"/>.</param>
        public int IndexOf(T item)
        {
            return _base.IndexOf(item);
        }

        /// <summary>
        /// Inserts an item to the <see cref="T:System.Collections.Generic.IList`1"/> at the specified index.
        /// </summary>
        /// <param name="index">The zero-based index at which <paramref name="item"/> should be inserted.</param><param name="item">The object to insert into the <see cref="T:System.Collections.Generic.IList`1"/>.</param><exception cref="T:System.ArgumentOutOfRangeException"><paramref name="index"/> is not a valid index in the <see cref="T:System.Collections.Generic.IList`1"/>.</exception><exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.IList`1"/> is read-only.</exception>
        public void Insert(int index, T item)
        {
            _base.Insert(index, item);
            OnItemChanged(this, new ItemChangedEventArgs<T>(index, item, ItemChangedEventType.ItemAdded));

        }

        /// <summary>
        /// Removes the <see cref="T:System.Collections.Generic.IList`1"/> item at the specified index.
        /// </summary>
        /// <param name="index">The zero-based index of the item to remove.</param><exception cref="T:System.ArgumentOutOfRangeException"><paramref name="index"/> is not a valid index in the <see cref="T:System.Collections.Generic.IList`1"/>.</exception><exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.IList`1"/> is read-only.</exception>
        public void RemoveAt(int index)
        {
            var item = _base[index];
            _base.RemoveAt(index);

            OnItemChanged(this, new ItemChangedEventArgs<T>(index, item, ItemChangedEventType.ItemAdded));
        }

        /// <summary>
        /// Gets or sets the element at the specified index.
        /// </summary>
        /// <returns>
        /// The element at the specified index.
        /// </returns>
        /// <param name="index">The zero-based index of the element to get or set.</param><exception cref="T:System.ArgumentOutOfRangeException"><paramref name="index"/> is not a valid index in the <see cref="T:System.Collections.Generic.IList`1"/>.</exception><exception cref="T:System.NotSupportedException">The property is set and the <see cref="T:System.Collections.Generic.IList`1"/> is read-only.</exception>
        public T this[int index]
        {
            get { return _base[index]; }
            set { _base[index] = value; }
        }

        #endregion
    }
}